Methods of bonding metal surfaces, and components therefor

ABSTRACT

A tray device that serves as a shipping tray and an assembly fixture to align a fabricated tape assembly in the bonding of steel locating hinge washers to a hinge assembly to facilitate doors-off/door-on processing through an automotive trim shop. The adhesive bonding system cures during the cathodic electro-cost primer bake cycle. The adhesive maintains an intimate, positive contact with both metal surfaces ensuring adequate bonding performance and maximized bonding surface area during a defined heat or bake cycle.

The present patent application claims priority from U.S. ProvisionalPatent Application Ser. No. 60/244,998 filed Nov. 1, 2000, and is adivisional application of U.S. patent application Ser. No. 10/039,722,now U.S. Pat No. 6,669,428, filed Oct. 24, 2001 in which a Petition toMake Special because of Actual Infringement was granted May 15, 2002.

The present invention relates generally to a tray device which serves asa shipping tray and an assembly fixture to align a fabricated tapeassembly in a method of bonding metal objects in place to facilitateassembly operations, and components used in such a method. Moreparticularly, the present invention relates to a unique process ofbonding in place metal objects, at least one of said objects havingpre-applied thereto an adhesive epoxy film or tape, and components usedin such a process.

BACKGROUND OF THE INVENTION

In the past, many techniques have been tried to make assemblyoperations, especially in automotive manufacture, more efficient. Thishas been especially true with respect to the locating of hinge washersin the door hinge assembly processes of automotive vehicles.

The techniques which have been tried in the past are inaccurate,expensive, complicated, cumbersome, slow, and subject to frequentmalfunction.

It is a desideratum of the present invention to provide a novel processfor bonding metal objects in place, and components used in such process,which avoid the animadversions of the prior art techniques.

SUMMARY OF THE INVENTION

The present invention provides a tray device which serves as a shippingtray and an assembly fixture to align a fabricated tape assembly forwashers, comprising: a main tray member divided into a predeterminednumber of tray sections; at least one locating pin being provided ineach said tray section; a plurality of posts affixed to said main traymember in each said tray section; and said posts in each said traysection being shaped, dimensioned and positioned to hold a predeterminedportion of said fabricated tape assembly.

The present invention also provides a washer device, comprising: a metalwasher; a heat-curable adhesive bonding composition pre-applied to afirst major surface of said metal washer; and said heat-curable adhesivebonding composition being capable of being cured to bond said firstmajor surface of said metal washer to an external metal substrate whenfirst major surface of said metal washer with said pre-appliedheat-curable adhesive bonding composition is brought into intimatecontact with said external metal substrate and is subjected to apredetermined heating until said pre-applied heat-curable adhesivecomposition cures to bond said first major surface of said metal washerand said external metal substrate together.

The present invention also provides a method of bonding a first metallicobject to a second metallic object, comprising the steps of: applying aheat-curable adhesive bonding composition to a predetermined percentageof a predetermined metallic surface of said first metallic object;bringing said heat-curable adhesive bonding composition applied to saidpredetermined metallic surface said first metallic object into intimatecontact with a predetermined metallic surface of said second metallicobject; and while said intimate contact is maintained, subjecting saidapplied heat-curable adhesive bonding composition to heat until saidadhesive composition cures to bond said predetermined metallic surfacestogether.

The present invention further provides a fabricated tape assembly,comprising: a release paper backing member; a film of structural epoxyadhesive applied to said release paper backing member; said film ofstructural epoxy adhesive being cut or perforated into a series ofadhesive annuli; said tape assembly being cut or perforated into aseries of square tape sections; and each said square tape sectioncontaining a predetermined and pre-arranged array of said adhesiveannuli.

The present invention also provides a tray device which serves as ashipping tray and an assembly fixture to align a fabricated tapeassembly for washers, comprising: a main tray member divided into apredetermined number of square tray sections; two locating pins beingprovided in each said square section; and a plurality of posts affixedto said main tray member in each said square tray section.

The present invention further provides a method of bonding metalsurfaces, comprising the steps of applying an adhesive epoxy film ortape to a first metal surface of a first object, wherein said adhesiveepoxy film or tape is capable of withstanding production phosphatingsolutions, cathodic electro-coat primer solutions, and cathodicelectro-primer bake temperatures. The adhesive epoxy film or tapeapplied to the first object is then brought into intimate contact with asecond metal surface of a second object. Thereafter, the first metalsurface, the adhesive epoxy film or tape, and the second metal surfaceare subjected to cathodic electro-coat baking until the adhesive epoxyfilm or tape cures to bond the first and second metal surfaces together.

An object of the present invention is to provide a method of bonding asdescribed hereinabove by preparing a die-cut cast epoxy film or tape ona release paper backing which is formed into predetermined shapes inaccordance with the first metal surface to be bonded.

Another object of the present invention is to provide a method asdescribed hereinabove which utilizes a high strength, heat cure,pre-applied, low tack, cast structural epoxy film or tape.

Yet a further object of the invention is to provide such an adhesiveepoxy film or tape at a defined thickness and shape which is mostefficient for the bonding of metal substrates as an assembly aid to postprocessing.

Another object of the invention is to provide such a method as describedhereinabove for use in the bonding of steel locating hinge washers tothe hinge assembly, to facilitate doors-off, doors-on processing throughthe trim shop and automotive assemblyYet a further object is to providea method as described hereinabove wherein the adhesive epoxy curesduring the cathodic electro-coat primer bake in assembly.

These and other objects, advantages and features of the presentinvention will become apparent to those persons skilled in this area oftechnology and to others when reading the detailed description set forthhereinbelow in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a top plan view of a novel shipping/assembly fixture tray ofthe present invention having assembled thereon a plurality of metalwashers on top of adhesive tape.

FIG. 2 depicts a cross-sectional drawing illustrating the assemblyprocess for bringing the metal objects into intimate contact with eachother prior to bonding.

FIG. 3 is a partial cross-sectional view which shows the tray post,backing, washer, and adhesive annulus.

DETAILED DESCRIPTION OF SOME PREFERRED EMBODIMENTS OF THE PRESENTINVENTION

A first preferred embodiment of the present invention will now bedescribed.

First, there is fabricated tape comprising a backing or release paper 1having applied thereto a film of structural epoxy adhesive. For example,the release paper 1 may preferably, but not necessarily, constitutetreated polyethylene coated kraft paper. Furthermore, the adhesive epoxymay preferably, but not necessarily, constitute a structural adhesivesupplied by 3M Corporation which is designated AF-126(0.08 wt).

The tape assemblage of the release paper 1 with its structural adhesivefilm thereon is then die cut into predetermined shapes and predetermineddimensions. For example, such an assemblage may be cut or perforatedinto a series of adhesive annuli 2, with a plurality of said adhesiveannuli 2 in a predetermined perforated section of such tape assemblage.For example, the tape assemblage may be cut or perforated into a seriesof square sections 3,4,5 or 6, with each such square section 3,4,5 or 6containing a three-by- three array of nine such adhesive annuli 2.

Four of such sections 3, 4, 5 and 6, each containing a three-by-threearray of nine adhesive annuli 2, are placed in a shipping/assemblyfixture tray 11 as illustrated in FIG. 1. Each square section 3, 4, 5 or6 is placed on the two associated locating pins 7 and 8 and nine posts12 of the tray 11 with the adhesive annuli 2 of the tape assemblagefacing upwardly.

A plurality of metal washers 9 which are countersunk on one side 10thereof are fabricated. The tray 11 serves as a shipping tray as well asan assembly fixture to align the die cut tape for the washers 9. Foreach square section 3, 4, 5 and 6 in the shipping/assembly fixture tray11, there are placed nine such countersunk washers 9 with thecountersunk surface 10 abutting an associated epoxy adhesive annulus 2.

The shipping/assembly tray is provided with a plurality of maleprotruding members or posts 12 upon which the release paper 1 with theadhesive annuli 2 are placed, and on top of which there are placed thewashers 9.

FIG. 3 is a partial cross-sectional view which shows the arrangement ofthe tray post 12, the release paper backing 1, the adhesive annulus 2,and the metal washer 9.

The shipping/assembly tray 11 as depicted in FIG. 1 is then sent to theautomotive assembly plants. A typical application includes the bondingof steel locating hinge washers 9 in the hinge assembly to facilitatedoors-off, doors-on processing through the trim shop.

When each washer 9 is removed from the tray 11, the adhesive annulus 2adheres to the countersunk side 10 of the washer 9 due to the tackinessof the adhesive annulus 2.

Each washer 9 is placed in a sandwich-like relation between two portions13 and 14 of the hinge assembly and maintained in intimate contacttherewith by way of a threaded bolt 15.

During the heat cure cycle, the adhesive annulus 2 is maintained inintimate, positive contact with both of the metal surfaces being bonded,to insure adequate bonding performance and maximize bond surface area.The epoxy annulus 2 has predetermined dimensions to be concentric withthe washer 9, but not coterminous therewith. Predetermined annularspaces 16 and 17 are provided within which the epoxy adhesive may spreadwithout running over the edges of the washer 9, and yet ensuring anadequate bonding performance.

The adhesive epoxy material is suitable for applications bonding metalsurfaces, such as galvanized, galvanneal, and cold rolled steel, whichmay be coated with metal forming lubricants. This special adhesivewithstands production phosphating solutions, cathodic electro-primersolutions, and cathodic electro-primer bake temperatures.

After the adhesive cures during the cathodic electro-primer bake andassembly, the hinge portions 13 and 14 can be disassembled leaving thesteel locating hinge washer 9 in place for later assembly.

The method includes all variations wherein application of the epoxyadhesive material can be at any point prior to the cathodic electro-coatbake in the body shop area of assembly or in the stamping plant.

Preferably, but not necessarily, the epoxy adhesive is not resistanceweld through capable.

Various modifications of the process and the components therefore asdescribed hereinabove are contemplated by the present invention.Therefore, while there have been set forth some preferred embodiments ofthe present invention, it should be understood that the presentinvention is not to be limited or restricted to the particularembodiments described in detail hereinabove which have been set forthfor illustrative purposes only.

1. A tray device comprising as a shipping tray and an assembly fixtureto align a fabricated tape assembly for washers, comprising: a main traymember divided into a predetermined number of square tray sections; twolocating pins provided in each square section; a plurality of postsaffixed to said main tray member in each said square tray section; saidfabricated tape assembly comprises a release paper backing member, afilm with structural epoxy adhesive applied to said release paperbacking member, said film of structural epoxy adhesive being cut orperforated into a series of adhesive annuli, said tape assembly beingcut or perforated into a series of square tape sections, and each saidsquare tape section containing a predetermined and pre-arranged array ofsaid adhesive annuli; each said square tape section being placed on twoof said locating pins, respectively; said adhesive annuli being placedon said posts; and said washers being placed on top of said adhesiveannuli.
 2. A tray device according to claim 1, wherein: said fabricatedtape assembly includes a plurality of adhesive annuli on a releasebacking substrate; said posts in each said tray section are shaped,dimensioned and positioned to hold thereon a predetermined portion ofsaid tape assembly; and each said post being shaped, dimensioned andpositioned to hold thereon one said adhesive annulus and one of saidwashers on top of said adhesive annulus.
 3. A tray device comprising asa shipping tray and an assembly fixture to align a fabricated tapeassembly for washers, comprising: a main tray member divided into apredetermined number of square tray sections; two locating pins beingprovided in each said square section; a plurality of posts affixed tosaid main tray member in each said square tray section; said fabricatedtape assembly includes a plurality of adhesive annuli on a releasebacking substrate; said posts of each said tray section are shaped,dimensioned and positioned to hold thereon a predetermined portion ofsaid tape assembly; and each said post is shaped, dimensioned andpositioned to hold thereon one said adhesive annulus and one of saidwashers on top of said adhesive annulus.
 4. A tray device comprising ashipping tray and an assembly fixture to align a fabricated tapeassembly for washers, comprising: a main tray member divided into apredetermined number of tray sections, at least one locating pin beingprovided in each said tray section; a plurality of posts affixed to saidmain tray member in each said tray section; and said posts in each saidtray section being shaped, dimensioned and positioned to hold apredetermined portion of said fabricated tape assembly; wherein: saidfabricated tape assembly includes a plurality of adhesive annuli on arelease backing substrate; and each post being shaped, dimensioned andpositioned to hold thereon one said adhesive annulus and one of saidwashers on top of said adhesive annulus.
 5. The device according toclaim 4, wherein: said fabricated tape assembly comprises a releasepaper backing member, a film of structural epoxy adhesive applied tosaid release paper backing member, said film of structural epoxyadhesive being cut or perforated into a series of adhesive annuli, saidtape assembly being cut or perforated into a series of square tapesections, and each said square tape section containing a predeterminedand pre-arranged array of said adhesive annuli; each said square tapesection being placed on two of said locating pins, respectively; saidadhesive annuli being placed on said posts; and said washers beingplaced on top of said adhesive annuli.